Add-ons

DownThemAll! by Nils Maier, Federico Parodi, others

The first and only download manager/accelerator built inside Firefox!

Password Exporter by Justin Scott (fligtar), Jorge Villalobos

This add-on allows you to export your saved passwords and disabled login hosts using XML or CSV files that can be imported later.

Note: This add-on won't work in Firefox 57. It may eventually if the APIs to access passwords are implemented.

Russian spellchecking dictionary by Alexander Slovesnik

Russian spellchecking dictionary

QuickNote by Leszek Życzkowski, Jed Brown, others

A simple note-taking extension.

Collector's Note Useful

Session Manager by Michael Kraft

Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.

Collector's Note Useful

UnMHT by arai_a

UnMHT allows you to view MHT (MHTML) web archive format files, and save complete web pages, including text and graphics, into a single MHT file in Firefox/SeaMonkey.

Collector's Note Useful

Speed Dial by Josep del Rio

Direct access to your most visited websites

Collector's Note Must have

ReminderFox by Tom Mutdosch, Daniel Lee, others

ReminderFox displays and manages lists of reminders and tasks. ReminderFox uses easy-to-use lists with warnings/alarms to remind you of all your important appointments.
Synchronize ReminderFox with other calendars as well.

Collector's Note Useful

Linkification by y5

Converts text links into genuine, clickable links...

Collector's Note Useful

Toolbar Buttons by Button Guy

Adds toolbar buttons to the customize toolbar window in several programs including Firefox, Thunderbird and SeaMonkey. Some of the buttons make commonly preformed actions quicker, others add new functionality.

Collector's Note Must have

United States English Spellchecker by jooliaan

This dictionary is no longer maintained. Use this dictionary instead.

Forecastfox Weather by Ensolis

Get international weather forecasts from AccuWeather.com and display them in any toolbar or statusbar with this highly customizable and unobtrusive extension.

Collector's Note Useful

Transliterator by Alex Benenson

As-you-type phonetic conversion of text from one alphabet to another, as well as transliteration/detransliteration of selected text anywhere within documents. Supports multiple languages and custom transliteration schemes.

MR Tech Disable XPI Install Delay by mrtech

Disables default delay when installing...

URL Fixer by eyeo GmbH

URL Fixer fixes common typos in URLs entered in the address bar. It will fix errors like "google.con" or "youtube,com". You have the option of being asked to confirm corrections before they are applied.

Collector's Note Useful